1. Field of the Invention
The present invention relates to a method for manufacturing a striking plate of a golf club head and, more particularly, to a method for manufacturing a striking plate with an integral wall and a bend portion by a stamping process subsequent to a high-temperature soft heat treatment, followed by a optional finishing machining process and then an age hardening process that precipitation hardens the striking plate, in order to provide an improved strength, elastic resilience and manufacturing accuracy for the resulting striking plate.
2. Description of Related Art
As shown in FIG. 1, a golf club head typically includes a main body 10 having a front opening 101 and a sleeve 102, and a striking plate 20 jointed to the main body 10 and engaged with an inner stepped portion 103 which is formed immediately within the inner circumference of the opening 101. Moreover, the striking plate 20 is generally provided with a plurality of parallel grooves 201 to increase friction useful in hitting a golf ball.
From a structural mechanical viewpoint, such embedding or welding joint of the plate 20 to the main body 10 absorbs impact produced by the ball and thus allows to transmit incomplete reaction from the plate 20 to the ball just before elastic deformation in the plate 20 reaches its climax. Consequently, the striking plate 20 limits the golf club head for hitting a long distance and such structure is unsuitable for hitting long distance. Additionally, the striking plate 20 within the inner circumference of the opening 101 of the main body 10 provides only a limited effective area for hitting the ball.
FIG. 2 shows another golf club head that includes a main body 10 provided with a rim 12 defining a front opening 11 and a striking plate 20 provided with an integral wall 21 and a bend portion 22. In addition to the fact of maximizing the effective area for hitting the ball, the bend portion 22 also impedes the transmission of impact from the plate 20 to the body 10. This results in a maximum elastic deformation in the plate 10 as it hits the balls and, in turn, an improved coefficient of restitution (COR) that may enable the golf club head to hit the ball long distance.
However, the striking plate 20 here is made by precision casting, a process in which various defects, such as slag eyes, sand inclusions, contraction cavities and blowholes, readily occur. These defects aggravate mechanical properties of the cast striking plate 20, which, as a casting, is weaken at its bend portion 22.